The post-enucleation socket syndrome (PESS) is a combination of features that result from a volume deficit of the orbital tissues surrounding the socket.
The main features of post-enucleation socket syndrome are:
1. Lost orbital volume; 2. Superior sulcus deformity; 3. Upper lid ptosis; 4. Lower lid laxity
These features should be addressed in appropriate order and with a team approach involving the prosthetist and the eye surgeon.
Following enucleation, the orbital tissues that once supported and protected the natural eye no longer serve a useful purpose and tend to shrink. This shrinkage is more pronounced in some people than others and occurs mostly during the first year or two. After that it stabilises somewhat, and subsequent changes have more to do with age and gravity than with shrinkage.
The orbital tissues that remain settle downward and the upper lid loses its support and drops down over the prosthesis. This pseudo-ptosis is accompanied by a degree of hollowness over the upper eyelid (superior sulcus deformity) and sometimes the upper tarsal plate distorts as well. Over time, the loss of orbital volume causes the prosthesis to tilt backwards and gaze upwards. This puts forward pressure on the lower eyelid which shallows the fornix and causes the lower lid to droop.